--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/giant.py	Sun Nov 19 18:10:23 2017 +1030
@@ -0,0 +1,163 @@
+#!/usr/bin/env python
+
+# pip install --user pyusb pycrc
+import crc16
+import exceptions
+import os
+import usb.core, usb.util, usb.control # https://github.com/pyusb/pyusb
+
+# USB details
+# Borrowed from http://allican.be/blog/2017/01/28/reverse-engineering-cypress-serial-usb.html
+vendorId = 0x0665
+productId = 0x5161
+interface = 0
+
+# Have to add one to these CRCs values before sending
+badvals = [0x28, 0x0d, 0x0a]
+
+class Timeout(exceptions.BaseException):
+    pass
+
+class FramingError(exceptions.BaseException):
+    pass
+
+class CRCError(exceptions.BaseException):
+    pass
+
+class GiantIPS(object):
+    PIWS = ['Reserved', 'InverterFault', 'BusOver', 'BusUnder', 'BusSoftFail', 'LineFail', 'OPVShort', 'InverterVoltsLow',
+                'InverterVoltsHigh', 'OverTemp', 'FanLocked', 'BattVoltsHigh', 'BattLowAlarm', 'Reserved(Overcharge)',
+                'BatterySHutdown', 'Reserved(BattDerate)', 'Overload', 'EEPROM', 'InverterOverCurrent', 'SelfTest',
+                'OPDCVoltsOver', 'BattOpen', 'CurrentSenseFail', 'BatteryShort', 'PowerLimit', 'PVVoltsHigh1',
+                'MPPTOverload', 'MPPTOverloadWarn', 'BattTooLowChrg', 'PVVoltsHigh2', 'MPPTOverload2', 'MPPTOverloadWarn2',
+                'BattTooLowChrg2', 'PVVoltsHigh3', 'MPPTOverload3', 'MPPTOverloadWarn3', 'BattTooLowChrg3']
+    def __init__(self):
+        dev = usb.core.find(idVendor = vendorId, idProduct = productId)
+        if dev.is_kernel_driver_active(interface):
+            dev.detach_kernel_driver(interface)
+        dev.set_interface_altsetting(0, 0)
+        self.dev = dev
+
+    def compose_msg(self, data):
+        crc = crc16.crc16xmodem(data)
+        crclow = crc & 0xff
+        crchigh = crc >> 8
+        if crclow in badvals:
+            crclow += 1
+        if crchigh in badvals:
+            crchigh += 1
+        data = data + chr(crchigh) + chr(crclow) + chr(0x0d)
+        while len(data) < 8:
+            data = data + b'\0'
+        return data
+
+    def tx_msg(self, data):
+        self.dev.ctrl_transfer(0x21, 0x9, 0x200, 0, self.compose_msg(data))
+
+    def rx_msg(self):
+        res = ''
+        tries = 200
+        while tries > 0 and '\r' not in res:
+            try:
+                d = self.dev.read(0x81, 8, 10)
+                res += ''.join([chr(i) for i in d if i != 0x00])
+            except usb.core.USBError as e:
+                if e.errno == 110: # timeout
+                    tries -= 1
+                    pass
+                else:
+                    raise
+
+
+        if tries == 0:
+            raise Timeout()
+        if res[0] != '(' or res[-1] != '\r':
+            raise FramingError()
+        crc = crc16.crc16xmodem(res[0:-3])
+        crclow = crc & 0xff
+        crchigh = crc >> 8
+        if ord(res[-3]) != crchigh or ord(res[-2]) != crclow:
+            #raise CRCError()
+            print('CRC error')
+
+        return res[1:-3]
+
+    def cmd(self, cmd):
+        self.tx_msg(cmd)
+        return self.rx_msg()
+
+    def getStatus(self):
+        d = self.cmd('QPIGS').split()
+        status = {}
+        if d[16][0] == '1':
+            status['SBUPrio'] = True
+        else:
+            status['SBUPrio'] = False
+        if d[16][1] == '1':
+            status['ConfigChg'] = True
+        else:
+            status['ConfigChg'] = False
+        if d[16][2] == '1':
+            status['BattVoltSteady'] = True
+        else:
+            status['BattVoltSteady'] = False
+        if d[16][3] == '1':
+            status['Charging'] = True
+        else:
+            status['Charging'] = False
+        if d[16][4] == '1':
+            status['SCC1Charging'] = True
+        else:
+            status['SCC1Charging'] = False
+        if d[16][5:] == '110':
+            status['ChargeType'] = 'SCC1'
+        elif d[16][5:] == '101':
+            status['ChargeType'] = 'AC'
+        else:
+            status['ChargeType'] = 'Both'
+        if d[20][0] == '1':
+            status['FloatCharge'] = True
+        else:
+            status['FloatCharge'] = False
+        if d[20][1] == '1':
+            status['Switch'] = True
+        else:
+            status['Switch'] = False
+        return {
+            'GridVolts' : float(d[0]),
+            'GridFreq' : float(d[1]),
+            'ACVolts' : float(d[2]),
+            'ACFreq' : float(d[3]),
+            'ACAppPower' : float(d[4]),
+            'ACActPower' : float(d[5]),
+            'LoadPct' : float(d[6]),
+            'BusVolts' : float(d[7]),
+            'BattVolts' : float(d[8]),
+            'BattChrCurr' : float(d[9]),
+            'BattCap' : float(d[10]),
+            'HSTemp' : float(d[11]),
+            'PVCurr1' : float(d[12]),
+            'PVVolt1' : float(d[13]),
+            'SCC1Volt' : float(d[14]),
+            'BattDisCurr' : float(d[15]),
+            'Status' : status,
+            'BattVoltOfs' : float(d[17]) / 0.01, # 10mV
+            'PVChrgPow1' : float(d[19]),
+            }
+
+    def getAlarms(self):
+        d = self.cmd('QPIWS')
+        res = {}
+        for i in range(min(len(d), len(self.PIWS))):
+            if d[i] == '1':
+                res[self.PIWS[i]] = True
+            else:
+                res[self.PIWS[i]] = False
+        return res
+
+def main():
+    ips = GiantIPS()
+    print(ips.cmd('QPI'))
+
+if __name__ == '__main__':
+    main()